Branching will work on a mobile device after configuring your mobile browser to allow pop ups.
Deactivate Pop up Blockers on iPhone:
http://osxdaily.com/2016/07/08/enable-disbale-pop-up-blocker-safari-ios
Deactivate Pop up Blockers on Android:
- Open Chrome.
- Tap the three vertical dot menu button in the top-right corner.
- Choose Settings > Site settings > Pop-ups.
- Turn on the toggle to allow pop-ups (for branching) or turn it off to block pop-ups